Copied from the Jetcat online manual. Seems it plainly states that the fuel solenoid will open & the pump will run. Doesn't matter if all the lines are hooked up or not, but recommended to disconnect them to keep from flooding the turbine.



The Test Functions Menu
The Manual mode is no longer implemented. Instead, a new expanded set of test functions are available from the Test–Functions Menu. To test the selected component, press the Change Value/Item key. To change the fuel pump or glow plug voltage when testing, while pressing the Change Value/Item key, press the ◄ - or ►+ key. The following functions are available ->
Value
Explanation
Pump TestVolt or
Purge FuelSystem
Opens fuel valve and runs the pump.
Default = 0.500 volts.
Note: Can be used to prime the pump and fuel system. Make sure the fuel line is disconnected from the turbine